Does Time and Size Matter in Retrograde Intrarenal Surgery? Results Analysis Using a Low-Pressure Technique.

PURPOSE: Kidney stone disease affects 5% of the population and is associated with non-negligible morbidity. Retrograde intrarenal surgery and percutaneous nephrolithotomy are the treatments of choice. We analyzed the results from our patients who underwent retrograde intrarenal surgery at controlled pressure. MATERIALS AND METHODS: We conducted an observational, descriptive, retrospective study of 403 patients who underwent retrograde intrarenal surgery at the Hospital Clínico Universitario Lozano Blesa (Zaragoza, Spain) between January 2013 and December 2019. RESULTS: The mean surgical time was 111.1 minutes, with a mean stone volume of 3.5 cm3 (maximum volume, 38.3 cm3). A total of 70 patients (17.3%) developed postoperative Clavien-Dindo complications-64 minor (91.4%) and 6 major (8.6%). In addition, 28 patients (6.9%) presented with an early complication (<3 months), with urinary tract infection and pyelonephritis being the most common. The stone-free rate was 69.0%, with a retreatment rate of 4.7%. CONCLUSIONS: Sex was statistically significantly related to the onset of minor Clavien postoperative complications (p = 0.001). Similarly, corticosteroid use was associated with the onset of major Clavien complications (p = 0.030). Neither surgical time nor stone volume was found to be statistically significantly related to the onset of Clavien postoperative complications or early complications.

Patient-specific bone geometry and segment inertia from MRI images for model-based analysis of pathological gait.

Patient-specific modeling is a vital component in the translation of computational multibody dynamics into clinical practice. Recent research has focused on ways to derive such models from medical imaging, but the process is usually time consuming and sensitive to operator skill. Here, we present methods to derive kinematic and inertial properties of body segments from MRI images, and condense them into a dynamically consistent patient-specific multibody model (PSM). We develop a semi-automated tool chain to classify bone, muscle and fat in the lower body and use optimization and geometrical methods to derive personalized bone meshes and segment inertial properties. The tool chain is applied to investigate the gait of a 12-yr old female with bone deformities. The patient-specific results are compared to those arising from generic scaled models with parameters based on regression equations. We found several kinematic and inertial differences between the two models, and overall the PSM resulted in markedly smaller angular and force residuals. The PSM was able to capture vital aspects of this patient׳s gait in the transverse plane that were overlooked by the generic model. These results are relevant to the use of multibody dynamics in the planning of surgical interventions, and form the basis for developing efficient and automatic methods to create patient-specific models.

Follow-up study on the utility of von Willebrand factor levels in the diagnosis of cardiac allograft vasculopathy.

BACKGROUND: Cardiac allograft vasculopathy (CAV) is the major cause of late death in patients undergoing heart transplantation (HT). The most validated method for its diagnosis is intravascular ultrasound (IVUS), and there are no sufficiently reliable non-invasive methods. von Willebrand factor (vWF) is a marker of endothelial dysfunction/activity that is rarely studied in the context of CAV. The purpose of this study was to determine whether patients with higher levels of vWF in the first year post-transplant will develop a greater degree of CAV. METHODS: A prospective study of 113 consecutive cardiac transplant recipients was initiated in January 2002. vWF determinations were performed at 1, 2, 4, 6, 9 and 12 months post-transplant, at the same time as biopsies. Coronary arteriography and IVUS were performed on the first and last follow-up visits. Heart-lung transplants, retransplants and pediatric transplants were excluded from the study. Patients who died in the first month and those who refused consent were also excluded. The final analysis included 72 patients and 405 vWF determinations. CAV was defined as an intimal thickening of >or=0.5 mm on follow-up versus baseline IVUS. Patients with CAV (n = 41) and without CAV (n = 31) after 1 year of follow-up were compared. RESULTS: Patients who developed CAV had a higher prevalence of prior dyslipidemia, ischemic heart disease as the cause of HT, and rate of rejection, as well as higher vWF levels (321 +/- 122 vs 243 +/- 100%, p < 0.05). The receiver-operator characteristic (ROC) curve showed that vWF values of 150% provided a sensitivity of 91%, and values of 400% a specificity of 91% (p < 0.0001). The variables associated with CAV in the multivariate analysis were prior dyslipidemia, rejections and vWF, both linearly and by groups. vWF levels of 300% to 400% increased the probability of developing CAV by 390%, and levels >400% by 500%, versus levels <200%. CONCLUSIONS: vWF levels determined in the first year post-transplant help to distinguish a subgroup of patients with a higher incidence of CAV.

Hemobilia: Informe de dos Casos y Revision de la Literatura / Hemobilia: report of 2 cases and review of the literature

La hemobilia es una entidad clinica relativamente comun que solo de manera ocasional se diagnostica en la practica medica. El presente trabajo comunica dos casos: uno de origen traumatico y otro sin este antecedente. Se revisa la literatura respecto a clasificacion, etiologia, manifestaciones, clinicas, diagnostico y tratamiento